402 ANNUAL REPORT OF THE Off. Doc. 



some days after the mnlelied fruit must be picked the difference in 

 color is much less. The lighter color of the tilled fruit is readily 

 and clearly explained. The coloring matter in the skin of the apple 

 like that in tlie leaves, consists of chlorophyl or leaf-green. The 

 coloring of ripening fruit is due to the changing of the chloropliyl 

 of the skin into the colored substances of autumnal tints. There- 

 tore since the sod fruit ripens earlier it colors earlier and in most 

 seasons better. 



The abnormally high color of the sod fruit in this orchard is 

 one of the most marked signs of the deleterious effect of the sod 

 on the trees. Everj^ man of experience has observed that when a 

 trees is starved, stunted, girdled, or injured, its foliage and its fruit 

 take on high color. Radiant color in fruit or leaf is often the hectic 

 flush of a diseased patient. The bright color of Ihe fruit of the sod- 

 mulched trees may be purchased at the expense of the vigor and the 

 health of the tree. 



The latter ripening period of the fruit on the tilled jdot would 

 be a defect with some varieties and in some localities but in general 

 in New York late ripening is an advantage. 



Fruit from both plots for the five years has been kept in cold 

 storage to test the relative keeping qualities. This Avork has been 

 in charge of Mr. G. H. Powell, the cold storage expert of the United 

 States Department of Agriculture, who wi'ites me in brief: "There 

 appears to have been little practical difference in keeping quality 

 between fruit from sod land and fruit picked a few days later from 

 the tilled land." 



There is but little diff'erence in the quality of the fruit when 

 specimens can be had at the same degree of maturity. But the tis- 

 sues of the sod-mulch fruit begin to break down so quickly after 

 l^arvesting that at any time after this period the tilled fruit is better 

 in qualitj. This has been tree in all of the five seasons, a fact af- 

 lirmed by repeated testing by those in charge of the experiment and 

 attested by many who have seen the fruit at the Geneva Station, at 

 horticultirral meetings and at institutes. The more pleasing color 

 of the sod-mulch fruit leads many to think it is of higher (lualiry 

 but it requires only a taste to convince to the contrary. 



In considering the causes of the differences noted between the 

 two systems of management we can do little more than state the 

 hypotheses which seem to account for the results. The experiment 

 is by no means concluded and definite reasons cannot be advanced 

 until all the proof is in. Yet it seems to me I am warranted in offer- 

 ing the following hypotheses: 



First. Plant food is more available in the tilled plot than in the 

 sod plot. That there is an abundance of the plant food necessary for 

 the welfare of the trees and the production of crops in both plots is 

 certain. For the trees in the tilled plots showed in all respects, 

 good feeding, and such trees in the sod-mulch plots as could get any 

 considerable portion of their roots in soil where there were no 

 grass roots, likewise seemed to be well fed. Moreover, two of the 

 chief elements of plant food, potash and phosphoric acid, were 

 added to a part of the trees in each plot for three successive sea- 

 sons and without appreciable results in either case. It is evident 



